Automatic draining system

ABSTRACT

An automatic draining system can include a driving mechanism, a first housing coupled to the driving mechanism, a vacuum pump and a bulkhead both coupled to the first housing, an inletting conduit and an outletting conduit both coupled to the bulkhead, a controlling device electrically coupled to the vacuum pump, a draining mechanism electrically coupled to the vacuum pump, and a first conduit and a second conduit both coupled to the first cylinder. The draining mechanism can include a first cylinder coupled to the bulkhead, a piston rod extending through the first cylinder; and
         a first piston assembly coupled to an end of the piston rod and received in the first cylinder. An end of the first conduit coupled to the first cylinder, the other end inserting into a pre-drained liquid. An end of the second conduit coupled to the first cylinder, the other end communicating with the outletting conduit.

FIELD

The subject matter herein generally relates to draining systems, andparticularly to an automatic draining system used in a vacuum workingenvironment.

BACKGROUND

Draining devices, such as draining pumps, can be used to removewater/oil or other liquid from a container. However, there is room forimprovement as to the efficiency of draining devices.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the present technology will now be described, by wayof example only, with reference to the attached figures.

FIG. 1 is an isometric view of an embodiment of an automatic drainingsystem, the automatic draining system including a draining device.

FIG. 2 is an exploded, isometric view of the automatic draining systemof FIG. 1.

FIG. 3 is an isometric view of the inner structure of the automaticdraining system of FIG. 1

FIG. 4 is an isometric view of the draining device of the automaticdraining system of FIG. 1.

FIG. 5 is a cross-sectional view of the draining device of FIG. 4, takenalong line II-II of FIG. 4.

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration,where appropriate, reference numerals have been repeated among thedifferent figures to indicate corresponding or analogous elements. Inaddition, numerous specific details are set forth in order to provide athorough understanding of the embodiments described herein. However, itwill be understood by those of ordinary skill in the art that theembodiments described herein can be practiced without these specificdetails. In other instances, methods, procedures and components have notbeen described in detail so as not to obscure the related relevantfeature being described. Also, the description is not to be consideredas limiting the scope of the embodiments described herein. The drawingsare not necessarily to scale and the proportions of certain parts havebeen exaggerated to better illustrate details and features of thepresent disclosure.

Several definitions that apply throughout this disclosure will now bepresented.

The term “coupled” is defined as connected, whether directly orindirectly through intervening components, and is not necessarilylimited to physical connections. The connection can be such that theobjects are permanently connected or releasably connected. The term“outside” refers to a region that is beyond the outermost confines of aphysical object. The term “substantially” is defined to be essentiallyconforming to the particular dimension, shape or other word thatsubstantially modifies, such that the component need not be exact. Forexample, substantially cylindrical means that the object resembles acylinder, but can have one or more deviations from a true cylinder. Theterm “comprising,” when utilized, means “including, but not necessarilylimited to”; it specifically indicates open-ended inclusion ormembership in the so-described combination, group, series and the like.

The present disclosure is described in relation draining systems, andparticularly to a automatic draining system used in a vacuum workingenvironment.

An automatic draining system for draining fluid, can include a drivingmechanism, a first housing coupled to the driving mechanism, a vacuumpump and a bulkhead both coupled to the first housing, an inlettingconduit and an outletting conduit both coupled to the bulkhead, acontrolling device in signal communication with the vacuum pump, adraining mechanism coupled to the vacuum pump, and a first conduit and asecond conduit both coupled to the first cylinder. The bulkhead and thefirst housing can define a first receiving cavity. The first receivingcavity can communicate with the vacuum pump. The inletting conduit andthe outletting conduit can both communicate with the first receivingcavity. The draining mechanism can include a first cylinder coupled tothe bulkhead, a piston rod extending through the first cylinder, andcouple to the driving mechanism; and a first piston assembly coupled toan end of the piston rod and received in the first cylinder. The firstconduit can include a first end coupled to the first cylinder, and asecond end in fluid communication with an external container receiving.The second conduit can include a first end coupled to the firstcylinder, and a second end in fluid communication with the outlettingconduit. The vacuum pump can be configured to suck up the air containedin the first receiving cavity. Such that the first receiving cavity canbe in a vacuum condition, enabling the pre-draining liquid to flowthrough the inletting conduit into the first receiving cavity. Thecontrolling device can be configured to detect a level of thepre-drained liquid in the first receiving cavity, and configured tocontrol the driving mechanism to move the piston rod. Such that thepre-drained liquid can be drained out.

FIGS. 1-2 illustrate an embodiment of an automatic draining system 200.The automatic draining system 200 can be configured to remove liquid,such as water and oil from a container (not shown), particularly can beapplied in a vacuum. The automatic draining system 200 can include ahousing 210, a vacuum pump 230, a controlling device 250, and a drainingdevice 100. The vacuum pump 230 can be coupled to the housing 210. Thecontrolling device 250 and the draining device 100 can be received inthe housing 210. The vacuum pump 230 and the draining device 100 can berespectively electrically connected to the controlling device 250.

Referring to FIGS. 3-4, the housing 210 can include a first housing 212and a second housing 214 coupled to each other, and a bulkhead 216positioned between the first housing 212 and the second housing 214. Thefirst housing 212 can define an opening 2121. The bulkhead 216 can coverthe opening 2121 and the second housing 214 can position at a side ofthe bulkhead 216 away from the first housing 212. The first housing 212and the bulkhead 216 can define an airtight first receiving cavity 2123,and the second housing 214 and the bulkhead 216 can define a secondreceiving cavity 2141. An inletting conduit 2161 and an outlettingconduit 2163 can be positioned on the bulkhead 216. An end of theinletting conduit 2161 can be received in the first receiving cavity2123, the other end of the inletting conduit 2161 can extend to theoutside and insert into a pre-draining liquid, such that thepre-draining liquid can be sucked into the first receiving cavity 2123.An end of the outletting conduit 2163 can be received in the firstreceiving cavity 2123, the other end can extend towards and communicatewith the outside.

The vacuum pump 230 can be positioned adjacent to the housing 210, andcoupled to the first housing 213 via a conduit (not labeled). The vacuumpump 230 can be configured to suck up the air contained in the firstreceiving cavity 2123. Such that the first receiving cavity 2123 can bein a vacuum condition, enabling the pre-draining liquid to flow throughthe inletting conduit 2161 into the first receiving cavity 2123.

The controlling device 250 can include a controller 252, a supportingrod 254, a float 256, and a receptor 258. The controller 252 can bepositioned on the bulkhead 216 and received in the second receivingcavity 2141. The supporting rod 254 can be perpendicularly positioned onthe bulkhead 216 and extend into the first receiving cavity 2123. Asensor 2541 can be positioned on the supporting rod 254. The float 256can be slidably sleeved on the supporting rod 254. The float 256 can beconfigured to float on the liquid contained in the first receivingcavity 2123. The sensor 2541 can be configured to detect a location ofthe float 256, and deliver and transmit an information of the locationof the float 256 to the controller 252. The receptor 258 can bepositioned on the bulkhead 216 adjacent to the controller 252, andcoupled to the draining device 100. In the illustrated embodiment, thereceptor 258 can be an electromagnetic valve. In at least oneembodiment, the receptor 258 can be other valves, such as, but notlimited to, a pneumatic valve or a hydraulic valve. Such that thereceptor 258 can be capable of controlling the inletting conduit 2161 toenable the liquid to flow through or cease from flowing in the inlettingconduit 2161 according to the location information of the float 2541sent by the sensor 52.

Referring to FIG. 4, the draining device 100 can be mounted on thebulkhead 216 and include a draining mechanism 10, a conduit 30 coupledto the draining mechanism 10, and a driving mechanism 50 coupled to thedraining mechanism 10. The driving mechanism 50 can be configured todrive the draining mechanism 10 to drain the liquid from the firstreceiving cavity 2123 through the conduit 30 into the outside.

Referring to FIG. 5, the draining mechanism 10 can be substantially acylinder-shape received in the first receiving cavity 2123. The drainingdevice 100 can include a first cylinder 11, a first cover 13, aconnecting member 15, a sealing member 16, a piston rod 17, and a firstpiston assembly 19. The first cover 13 and the connecting member 15 canbe positioned on opposite ends of the first cylinder 11, respectively.The piston rod 17 can be inserted through the connecting member 15 andcan be partially received in the first cylinder 11. The sealing member16 can be positioned between the piston rod 17 and the connecting member15. The first piston assembly 19 can be sleeved on the piston rod 17 andreceived in the first cylinder 11.

The first cylinder 11 can be substantially a hollow cylinder and definea cavity 111 along an axis.

The first cover 13 can be arranged and mounted on an end of the firstcylinder 11, and define a first draining hole 131 at a side. The firstdraining hole 131 can communicate with the cavity 111 and can be used tocouple to the conduit 30.

The connecting member 15 can be substantially cylinder-shape andpositioned on the bulkhead 216. The connecting member 15 can be coupledto an end of the first cylinder 11 opposite to the first cover 13. Theconnecting member 15 can define a through hole 151, a second draininghole 153, and a first air inlet 154. The through hole 151 can beoriented along an axis of the connecting member 15 and can communicatewith the cavity 111. The second draining hole 153 can be defined at aperiphery of the connecting member 15 and adjacent to the first cylinder11, and the second draining hole 153 can communicate with the throughhole 151 and can be oriented along a radial direction of the connectingmember 15. The first air inlet 154 can be defined at a periphery of theconnecting member 15 away from the first cylinder 11, and configured tocouple to an external air source (not shown) and couple to the receptor258. The receptor 258 can be capable of controlling the first air inlet154 to enable the air flow to blow through or cease from blowing in thefirst air inlet 154. The connecting member 15 can be further equippedwith a mounting portion 155. The mounting portion 155 can protrude froma middle part of the periphery of the connecting member 15, and can besubstantially an annular flange. The draining device 100 can be mountedto the bulkhead 216 through the mounting portion 155. The mountingportion 155 can define a mounting slot 1551 configured to provide a roomfor a sealing member, such as, but not necessary limited to, an o-ring,such that the draining device 100 can be hermetically sealed whenmounted to the bulkhead 216.

In the illustrated embodiment, the sealing member 16 can be an o-ring.The sealing member 16 can be arranged in the connecting member 15 andsleeved on the piston rod 17

The piston rod 17 can be substantially a stepped shaft, and can slidablyinsert through the through hole 151 and the sealing member 16. Thepiston rod 17 can include a main body 171, a first fixing portion 173and a second fixing portion 175. The first fixing portion 173 and thesecond fixing portion 175 can be formed on opposite ends of the mainbody 171 of the piston rod 17, and the first fixing portion 173 can bereceived in the cavity 111. The main body 171 can be slidably insertedthrough the through hole 151 and define a first receiving hole 1711 onan end adjacent to the first fixing portion 173. In the illustratedembodiment, the first receiving hole 1711 can be a blind hole and can bedefined at a periphery of the main body 171, extending outwardly along aradially direction of the main body 171. An inner diameter of the firstreceiving hole 1711 can be 0.5 millimeter or less than 0.5 millimeter.An outer diameter of the first fixing portion 173 can be less than anouter diameter of the main body 171. The first fixing portion 173 can beequipped with a connecting portion 1731 on an end away from the mainbody 171, and an external thread (not labeled) on an outer surface ofthe connecting portion 1731. The first fixing portion member 173 canfurther define a second receiving hole 1733 oriented along an axis on anend away from the main body 171. The second receiving hole 1733 canextend to connect with the first receiving hole 1711. An inner diameterof the second receiving hole 1733 can be 1 millimeter or less than 1millimeter. The first receiving hole 1711 and the second receiving hole1733 can be configured to receive gas dissolved in the liquid, such thatthe draining mechanism 10 can operate fluently. In an alternativeembodiment, the first receiving hole 1711 and the second receiving hole1733 can be omitted. A structure of the second fixing portion 175 can besubstantially the same as a structure of the first fixing portion 173.The second fixing portion 175 can include a connecting portion 1751.

The first piston assembly 19 can be positioned on the first fixingportion 173 and can slide in the cavity 111 along with the piston rod17, to enable the draining mechanism 10 to work. The first pistonassembly 19 can divide the cavity 111 into a first cavity 1111 adjacentto the first cover 13 and a second cavity 1113 away from the first cover13. The first piston assembly 19 can include a mounting base 191, amagnetic member 193, a piston body 195, a sealing ring 197, and asecuring member 199.

The mounting base 191 can be sleeved on the first fixing portion 173 andcan resist against the main body 171. A cushion 1911 can be located on asurface of the mounting base 191 facing the connecting member 15. Whenthe first piston assembly 19 slides towards the connecting member 15,the cushion 1911 can buffer the first piston assembly 19, and protectthe mounting base 191 and the connecting member 15 from damage. Themagnetic member 193 can be sleeved on an end of the mounting base 191away from the main body 171, and can be used to couple to an outermagnetic sensor and a controller, such that the outer magnetic sensorcan sense a location of the first piston assembly 191 and the controllercan control the draining device 100 to work according to the location.The piston body 195 can be sleeved on the first fixing portion 171adjacent to the first cover 13. A cushion 1951 can be located on asurface of the piston body 195 facing the first cover 13. When the firstpiston assembly 19 slides towards the first cover 13, the cushion 1911can buffer and protect the piston body 195 and the first cover 13 fromdamage. The sealing ring 197 can be sleeved on the piston body 195 andcan resist against an inner surface of the cavity 111. In theillustrated embodiment, the securing member 199 can be a nut. Thesecuring member 199 can be sleeved on the first fixing portion 173adjacent to the piston body 195, and thread to the connecting portion1731, such that the mounting member 191, the magnetic member 193, andthe piston body 195 can be arranged side by side and resist on the mainbody 171.

In the illustrated embodiment, there can be two conduits 30. The twoconduits 30 can be coupled to the first draining hole 131 and the seconddraining hole 153, respectively. Each of the two conduits 30 can includea main conduit 32, a first conduit 34, and a second conduit 36. An endof the main conduit 32 can communicate with the first draining hole 131.The first conduit 34 and the second conduit 36 can be spaced from eachother, and communicate with each other on an end to couple with the mainconduit 32. Such that, the conduit 30 can be formed substantially as aY-shape. A first check valve 341 can be positioned in the first conduit34, and enable the pre-drained liquid to flow from the container (notshown) into the main conduit 32 and the first conduit 34, towards thefirst cavity 111. An end of the second check valve 361 away from themain conduit 32 can communicate with the outletting conduit 2163, andcan provide a second check valve 361. The second check valve 361 can beconfigured to enable the pre-drained liquid to flow from the firstcavity 111 into the main conduit 32, the second conduit 36 and theoutletting conduit 2163, towards an outer space. In an alternativeembodiment, there can be one or more conduits 30. The second draininghole 153 can be omitted if there is only one conduit 30.

In the illustrated embodiment, the driving mechanism 50 can besubstantially a pneumatic device and can be coupled to the drainingmechanism 10, and received in the second receiving cavity 2141. Thedriving mechanism 50 can be configured to reciprocate the piston rod 17in the cavity 111. A structure of the driving mechanism 50 can besimilar to a structure of the draining mechanism 10. The drivingmechanism 50 can include a second cylinder 51, a second cover 53, and asecond piston assembly 55. The second cylinder 51 can be positioned onthe connecting member 15 away from the first cylinder 11. The secondcylinder 51 can define a cavity 511 configured to receive an end of thepiston rod 17. The cavity 511 can communicate with the first air inlet154. The second cover 53 can be positioned on an end of the secondcylinder 51 away from the connecting member 15. The second cover 53 candefine a second air inlet 531 communicating with the cavity 511, andconfigured to couple to the outer air source and the receptor 258. Thereceptor 258 can be capable of controlling the second air inlet 531 toenable the air flow to blow through or cease from blowing in the secondair inlet 531. The second piston assembly 55 can be mounted on thesecond fixing portion 175 of the piston rod 17, and can slide in thecavity 511. A structure of the second piston assembly 55 can besubstantially identical to the first piston assembly 19.

In assembly, the piston rod 17 can be inserted through the connectingmember 15 and the sealing member 16, the first piston assembly 19 can bemounted on the first fixing portion 173 of the piston rod 17, and thesecond piston assembly 55 can be mounted on the second fixing portion175. The first cylinder 11 can be arranged on the connecting member 15corresponding to the first piston assembly 19, the second cylinder 51can be arranged on the connecting member 15 corresponding to the secondpiston assembly 55. The first cover 13 can be positioned on the firstcylinder 11 and the second cover 53 can be positioned on the secondcylinder 51. The two conduits 30 can be coupled to the first draininghole 131 and the second draining hole 153, respectively. The controllingdevice 250, the inletting conduit 2161, the outletting conduit 2163, andthe draining device 100 can be mounted to the bulkhead 216, the secondconduit 36 can be communicating with the outletting conduit 2163. Thebulkhead 216 can be positioned on the first housing 212 and cover thefirst receiving cavity 2123. The second housing 214 can be mounted tothe first housing 212. The vacuum pup 230 can be coupled to the housing210.

In operation, the inletting conduit 2161 can be inserted in to thepre-drained liquid, and the vacuum pump 230 can be started. Thepre-drained liquid can be sucked into the first receiving cavity 2123.The float 254 can float on the pre-drained liquid. The sensor 256 candetect the location of the float 254, and deliver and transmitinformation of the location to the controller 252. When a level of thepre-draining liquid rises and reach a certain level, the controller 252can controlling the receptor 258 to enable the first air inlet 154 andthe second air inlet 531 to communicate with the external air source,such that draining device 100 can be started. The driving mechanism 50can drive the piston rod 17 and the first piston assembly 19 to slideback and forth in the first cylinder 11. When the first piston assembly19 moves close to the first cover 13, a volume of the first cavity 1111can be reduced, and the liquid contained in the first cavity 11 can beforced to flow through the first draining hole 131, the main conduit 32,the second conduit 36 of one of the two conduits 30 corresponding to thefirst draining hole 131, and the outletting conduit 2163. At the sametime, a volume of the second cavity 1113 can be enlarged, and a pressuretherein can be lowered, such that the pre-drained liquid can be drawnfrom the container through the main conduit 32 and the first conduit 34or the other one of the two conduits 30 corresponding to the seconddraining hole 153, and through the second draining hole 153, towards thesecond cavity 1113. When the first piston assembly 19 moves away fromthe first cover 13, the volume of the first cavity 1111 can be enlarged,and the pressure therein can be lowered, such that the pre-drainedliquid can be drawn from the container through the main conduit 32 andthe first conduit 34 corresponding to the first draining hole 131, andthrough the first draining hole 131, towards the first cavity 1111. Atthe same time, the volume of the second cavity 1113 can be reduced, andthe liquid therein can be forced to flow through the second draininghole 153, the main conduit 32, the second conduit 36 corresponding tothe second draining hole 153, and the outletting conduit 2163. Thepiston rod 17 can reciprocate the first piston assembly 19, and thevacuum pump 230 can keep working such that the draining mechanism 10 cankeep the pre-drained liquid flowing in the first receiving cavity 2123.The level of the pre-drained liquid in the first cavity 2123 can befallen while draining. When the level is fallen and reach a certainlevel, the controller 252 can stop the vacuum pump 230 and the drivingmechanism 30, such that the draining device 100 can be stopped fromdraining.

In an alternative embodiment, the driving mechanism 50 can be otherdriving devices, such as, but not limited to, a four-bar mechanismdriven by a motor, a feed screw-nut mechanism, or other linear drivingmechanism, such that the driving mechanism 50 can drive the piston rod17 and the first piston assembly 19 to reciprocate in the first cavity11. The first receiving hole 1733 and the second receiving hole 1711 canbe omitted. The first cover 13 can be omitted, such that the firstcylinder 11 can be formed as a hollow structure with a bottom (13) on aend, and the first draining 131 coupled to the conduit 30 can be definedon the bottom (13). Similarly, the second cover 53 can be omitted.

In an alternative embodiment, the conduit 30 can be other geometricshapes, for example, the main conduit 32 can be omitted, and the firstconduit 32 and the second conduit 34 can be coupled to and communicatingwith the cavity 11 respectively, but spaced from each other. Such thatthe liquid in the first conduit 32 and the second conduit 34 can flow intwo opposite directions.

In an alternative embodiment, the first check valve 341 and the secondcheck valve 361 can be omitted. Such that the pre-drained liquid can besucked from the first receiving cavity 2123 through the first conduit 34into the first cavity 1111, and flow towards the outside through thesecond conduit 36.

In an alternative embodiment, the first cover 13 and the connectingmember 15 can be omitted. Such that the first cylinder 11 can be aintegral structure defining a through hole to receive the piston rod 17,and defining the first draining hole 131 and the second draining hole153. The second cylinder 51 can define a first air inlet 154 tocommunicate with the external air resource. When assembly, the firstcylinder 11 can be mounted to the bulkhead 216 and the second cylinder51 can be mounted to the first cylinder 11.

The embodiments shown and described above are only examples. Manydetails are often found in the art such as the other features of anautomatic draining system. Therefore, many such details are neithershown nor described. Even though numerous characteristics and advantagesof the present technology have been set forth in the foregoingdescription, together with details of the structure and function of thepresent disclosure, the disclosure is illustrative only, and changes maybe made in the detail, including in matters of shape, size andarrangement of the parts within the principles of the present disclosureup to, and including the full extent established by the broad generalmeaning of the terms used in the claims. It will therefore beappreciated that the embodiments described above may be modified withinthe scope of the claims.

What is claimed is:
 1. An automatic draining system for draining fluid,the automatic draining system comprising: a first housing; a drivingmechanism coupled to the first housing; a vacuum pump coupled to thefirst housing; a bulkhead coupled to the first housing, the bulkhead andthe first housing cooperatively defining a first receiving cavity whichcommunicates with the vacuum pump; an inletting conduit coupled to thebulkhead and communicating with the first receiving cavity; anoutletting conduit coupled to the bulkhead and communicating with thefirst receiving cavity; a controlling device in signal communicationwith the vacuum pump; and a draining mechanism coupled to the vacuumpump, the draining mechanism comprising: a first cylinder coupled to thebulkhead; a piston rod extending through the first cylinder, and coupleto the driving mechanism; and a first piston assembly coupled to an endof the piston rod and received in the first cylinder; a first conduithaving a first end coupled to the first cylinder, and a second end influid communication with an external container receiving a pre-drainedliquid therein; and a second conduit having a first end coupled to thefirst cylinder, and a second end in fluid communication with theoutletting conduit, wherein the vacuum pump is configured to suck up theair contained in the first receiving cavity, such that the firstreceiving cavity is in a vacuum condition, enabling the pre-drainingliquid to flow through the inletting conduit into the first receivingcavity; and the controlling device is configured to detect a level ofthe pre-drained liquid in the first receiving cavity, and configured tocontrol the driving mechanism to move the piston rod, such that thepre-drained liquid can be drained out.
 2. The automatic draining systemof claim 1, wherein the automatic draining system further comprises asupporting rod mounted on the bulkhead and extending into the firstreceiving cavity, a float slidably sleeved on the supporting rod, areceptor mounted on the bulkhead, and a sensor positioned on thesupporting rod; the float is capable of floating on the pre-drainedliquid, the sensor is configured to detect a location of the float, anddeliver and transmit an information of the location of the float to thereceptor; the receptor is coupled to the driving mechanism and isconfigured to control the driving mechanism to work.
 3. The automaticdraining system of claim 1, wherein the automatic draining systemfurther comprises a first check valve positioned in the first conduit,and a second check valve positioned in the second conduit; the firstcheck valve is configured to enable fluid to flow from the firstcylinder towards the first conduit; the second check valve is configuredto enable fluid to flow from the second conduit towards the firstcylinder.
 4. The automatic draining system of claim 1, wherein thedraining mechanism further comprises a connecting member cover on thefirst cylinder; the piston rod comprises a main body extending throughthe connecting member; a sealing member is positioned between the mainbody and the connecting member.
 5. The automatic draining system ofclaim 4, wherein the piston rod further comprises a first fixing portionand a second fixing portion on opposite ends of the main body; the firstpiston assembly is sleeved on the first fixing portion and the drivingmechanism is positioned on the second fixing portion.
 6. The automaticdraining system of claim 5, wherein he main body defines a firstreceiving hole at a periphery thereof; the receiving hole is adjacent tothe first fixing portion and extends along radial direction of the mainbody; the first fixing portion defines a second receiving hole on an endthereof; the second receiving hole is away from the main body andextending along an axis of the first fixing portion; the secondreceiving hole extends into the main body and communicates with thefirst receiving hole.
 7. The automatic draining system of claim 4,wherein the first piston assembly comprises a mounting base mounted onthe piston rod, and a magnetic member sleeved on the mounting base. 8.The automatic draining system of claim 7, wherein he first pistonassembly further comprises a piston body sleeved on the piston rod; thepiston rod is positioned on a side of the magnetic member adjacent tothe first cover.
 9. The automatic draining system of claim 8, whereinthe first piston assembly further comprises a sealing ring positioned onan outer surface of the piston rod and resisting against an innersurface of the cover.
 10. The automatic draining system of claim 8,wherein the first piston assembly further comprises two cushions; one ofthe cushion is positioned on a surface of the mounting base facing theconnecting member; the other cushion is positioned on a surface of thepiston body departing from the magnetic.
 11. The automatic drainingsystem of claim 8, wherein the piston rod further comprises a connectingportion on an end of the main body; the first piston assembly furthercomprises a securing member, the securing member is sleeved on thepiston rod adjacent to the piston body.
 12. The automatic drainingsystem of claim 11, wherein the connecting portion is equipped with anexternal thread on an outer surface thereof, the securing member threadsto the connecting portion to fix the first piston assembly.
 13. Theautomatic draining system of claim 11, wherein the driving mechanismcomprises a second cylinder and a second piston assembly, the secondcylinder is coupled to the first cylinder, an end of the piston rod awayfrom the first cylinder is received in the second cylinder; the secondpiston assembly is sleeved on the piston rod and slidably received inthe second cylinder.
 14. An automatic draining system comprising: afirst housing; a driving mechanism coupled to the first housing; avacuum pump coupled to the first housing; a bulkhead coupled to thefirst housing, the bulkhead and the first housing cooperatively defininga first receiving cavity which communicates with the vacuum pump; aninletting conduit coupled to the bulkhead and communicating with thefirst receiving cavity; an outletting conduit coupled to the bulkheadand communicating with the first receiving cavity; a controlling devicein signal communication with the vacuum pump; and a draining mechanismcoupled to the vacuum pump, the draining mechanism comprising: a firstcylinder coupled to the bulkhead; a piston rod extending through thefirst cylinder, and couple to the driving mechanism; and a first pistonassembly coupled to an end of the piston rod and received in the firstcylinder; a first conduit having a first end coupled to the firstcylinder, and a second end in fluid communication with an externalcontainer receiving a pre-drained liquid therein; and a second conduithaving a first end coupled to the first cylinder, and a second end influid communication with the outletting conduit.
 15. The automaticdraining system of claim 14, wherein the automatic draining systemfurther comprises a supporting rod mounted on the bulkhead and extendinginto the first receiving cavity, a float slidably sleeved on thesupporting rod, a receptor mounted on the bulkhead, and a sensorpositioned on the supporting rod; the float is capable of floating onthe pre-drained liquid, the sensor is configured to detect a location ofthe float, and deliver and transmit an information of the location ofthe float to the receptor; the receptor is coupled to the drivingmechanism and is configured to control the driving mechanism to work.16. The automatic draining system of claim 14, wherein the automaticdraining system further comprises a first check valve positioned in thefirst conduit, and a second check valve positioned in the secondconduit; the first check valve is configured to enable fluid to flowfrom the first cylinder towards the first conduit; the second checkvalve is configured to enable fluid to flow from the second conduittowards the first cylinder.
 17. The automatic draining system of claim14, wherein the draining mechanism further comprises a connecting membercover on the first cylinder; the piston rod comprises a main bodyextending through the connecting member; a sealing member is positionedbetween the main body and the connecting member.
 18. The automaticdraining system of claim 17, wherein the piston rod further comprises afirst fixing portion and a second fixing portion on opposite ends of themain body; the first piston assembly is sleeved on the first fixingportion and the driving mechanism is positioned on the second fixingportion.
 19. The automatic draining system of claim 18, wherein he mainbody defines a first receiving hole at a periphery thereof; thereceiving hole is adjacent to the first fixing portion and extends alongradial direction of the main body; the first fixing portion defines asecond receiving hole on an end thereof; the second receiving hole isaway from the main body and extending along an axis of the first fixingportion; the second receiving hole extends into the main body andcommunicates with the first receiving hole.
 20. An automatic drainingsystem comprising: a first housing; a vacuum pump coupled to the firsthousing; a bulkhead coupled to the first housing, the bulkhead and thefirst housing cooperatively defining a first receiving cavity whichcommunicates with the vacuum pump; an inletting conduit coupled to thebulkhead and communicating with the first receiving cavity; anoutletting conduit coupled to the bulkhead and communicating with thefirst receiving cavity; a controlling device in signal communicationwith the vacuum pump; and a draining mechanism coupled to the vacuumpump, the draining mechanism comprising: a first cylinder coupled to thebulkhead; the first cylinder a piston rod extending through the firstcylinder; and a first piston assembly coupled to an end of the pistonrod and received in the first cylinder; a first conduit having a firstend coupled to the first cylinder, and a second end in fluidcommunication with an external container receiving a pre-drained liquidtherein; and a second conduit having a first end coupled to the firstcylinder, and a second end in fluid communication with the outlettingconduit.